... "steps on the gas" and requires extra power. PLUG-IN HYBRIDS:A plug-in hybrid electric vehicle (PHEV), also known as a plug-in hybrid, is a hybrid electric vehicle with rechargeable batteries that ... for supplemental recharging. Parallel hybrids are more efficient for highway driving than in urban stop-and-go conditions. SERIES HYBRIDS:In series hybrids, only the electric motor drives ... cost is higher than a pure parallel. Degrees of hybridization:Degrees of hybridization:FULL HYBRID: Full hybrid, sometimes also called a strong hybrid, is a vehicle that can run on just the engine,...